Film maker Peter Jackson wants to scare children with his latest movie - and perhaps even a few grown ups.

The first of the Hobbit movie trilogy - The Hobbit: An Unexpected Journey- is about to hit theatres, and Jackson says he's tried to hold true to its roots as a children's fantasy story, with scary bits.

"If they're scared of the trolls great, if they're scared of the goblins great, they know there are no goblins, they know there are no trolls, it's a safe kind of danger," he says.

The film, produced by MGM and Time Warner Inc, is the fourth in the Oscar-winning Jackson's blockbuster "Lord of the Rings" film franchise, based on the books of author J.R.R. Tolkien.

It follows the journey of hobbit Bilbo Baggins, reluctantly pushed into travelling with 13 dwarves to steal treasure from a dragon and regain their homeland. During his travels, he comes by the ring that he later passes onto kinsman Frodo Baggins, which was at the core of the "Rings" trilogy.

Jackson says he's worked to keep distance between the Hobbit, published in 1937, and the much darker Lord of the Rings, which came out nearly 20 years later.

"The Lord of the Rings has an apocalyptic sort of heavy themic end-of-the world quality to it, which the Hobbit doesn't, which is one of the delights of it," he said.

POMPOUS AND SMALL MINDED

The pointy eared, hairy footed hobbit Bilbo is played by British actor Martin Freeman, who says he's tried to make Bilbo his own creation, a character audiences can root for despite his initial pomposity and small mindedness.

"You have to be able to follow him for the duration of the film, but I wanted him to be open and changeable and ready to be surprised," Freeman said.

A key scene is an encounter in a cave between Bilbo and the creature Gollum, reprised in full computer generated splendour by Andy Serkis with the distinctive throaty whisper.

"It was a very rich experience," he said, adding that playing Gollum again was "an absolute thrill".

Such is the affection for the creature, who calls the magic ring "Precious", that a 13 metre sculpture of Gollum hangs in the airport terminal at Wellington, which regards itself as the spiritual home of the Tolkien films and terms itself the "Middle of Middle Earth".

Returning actors from the Rings trilogy, many of whom have only passing mention in the book, were no less enthusiastic. Ian McKellen returns for a leading role as the wispy-haired, grey bearded wizard, Gandalf, while Cate Blanchett is the elven queen Galadriel and Elijah Wood appears as Frodo Baggins.

"You couldn't not come back, you had to come back," says Hugo Weaving, the leader of the elves, Elrond.

HOBBIT - A FRAUGHT JOURNEY

The Hobbit film journey has not been without its setbacks.

Metro-Goldwyn-Mayer, owners of the film rights to the Tolkien books, had financial woes, prompting original director Guillermo del Toro to pull out and Jackson, already script writer and executive producer, to step in.

A major labour dispute prompted threats to move production out of New Zealand, and was solved by changing labour laws, while Jackson suffered a perforated ulcer and underwent surgery, delaying the film still further.